Studies were performed in the following areas: (1) role of opsonin depletion in accelerating the terminal phase of cryptococcosis, (2) radioimmunoassay of cryptococcal antigen and antibody, (3) biochemical differences among the two sub-groups of C. neoformans, (4) mechanism by which the systemic antifungal drug, flucytosine, produces bone-marrow toxicity and (5) role of lymphokines in recovery from ringworm. BIBLIOGRAPHIC REFERENCES: Bennett, J. E.: Amphotericin B binding serum betalipoprotein. In Iwata, K. (Ed.): Recent Advances in Medical and Veterinary Mycology. Tokyo, University of Tokyo Press, 1977, pp 107-109. Bennett, J. E., Kwon-Chung, K. J., and Howard, D. H.: Epidemiologic differences among serotypes of Cryptococcus neoformans. Amer. J. Epidemiol. 105: 582-586, 1977.